1. Field of the Invention
The present invention relates to a semiconductor device that protects a gallium nitride high electron mobility field effect transistor (abbreviated as GaN-HEMT, hereinafter) from surge breakdown and to a method of manufacturing the semiconductor device.
2. Background Art
When a surge current of several amperes flows into a GaN-HEMT from the outside via a gate pad, part or the whole of the GaN-based epitaxial layer right below the gate electrode breaks or degrades and the GaN-HEMT breaks or degrades. A semiconductor device in which a vertical PN diode is connected to a GaN-HEMT to bypass a surge current has therefore been proposed (see, for example, Japanese Patent Laid-Open No. 2010-040814.